Generating typespecs

[maurocchi]

Hi, I recently found this library out and it looks really interesting!

I noted that it could create a struct at compile-time inspecting the request/response schema, but it does not define the typespecs with all the fields included (just the trivial type @type t :: %__MODULE__{}).

Is there any plan to do that?

[mbuhot]

HI @enerdgumen, I don't think anyone is planning to work on typespec generation, but it would be a welcome feature addition to the library 👍

I'd suggest phasing it in, something like:

1. Allow users to manually define their own @type t :: ... along side their schema.
2. Provide a function to generate a type from an %OpenApiSpex.Schema{} struct - simple structs with primitive fields shouldn't be too hard, but polymorphic schemas are tricky. Users could opt-in to this feature for schemas where it is supported.
3. Once the type generation function can cover most schemas, then we can make it the default behaviour of the OpenApiSpex.schema macro.